/*
 * MIT License
 *
 * Copyright (c) 2023 北京凯特伟业科技有限公司
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
package com.je.bpm.engine.impl.cmd;

import com.je.bpm.engine.impl.Page;
import com.je.bpm.engine.impl.asyncexecutor.AcquiredTimerJobEntities;
import com.je.bpm.engine.impl.asyncexecutor.AsyncExecutor;
import com.je.bpm.engine.impl.interceptor.Command;
import com.je.bpm.engine.impl.interceptor.CommandContext;
import com.je.bpm.engine.impl.persistence.entity.TimerJobEntity;

import java.util.Calendar;
import java.util.GregorianCalendar;
import java.util.List;

/**
 * 获取计时器作业
 */
public class AcquireTimerJobsCmd implements Command<AcquiredTimerJobEntities> {

    private final AsyncExecutor asyncExecutor;
    
    public AcquireTimerJobsCmd(AsyncExecutor asyncExecutor) {
        this.asyncExecutor = asyncExecutor;
    }

    @Override
    public AcquiredTimerJobEntities execute(CommandContext commandContext) {
        AcquiredTimerJobEntities acquiredJobs = new AcquiredTimerJobEntities();
        List<TimerJobEntity> timerJobs = commandContext.getTimerJobEntityManager()
                .findTimerJobsToExecute(new Page(0, asyncExecutor.getMaxAsyncJobsDuePerAcquisition()));

        for (TimerJobEntity job : timerJobs) {
            lockJob(commandContext, job, asyncExecutor.getAsyncJobLockTimeInMillis());
            acquiredJobs.addJob(job);
        }

        return acquiredJobs;
    }

    protected void lockJob(CommandContext commandContext, TimerJobEntity job, int lockTimeInMillis) {

        // This will trigger an optimistic locking exception when two concurrent executors
        // try to lock, as the revision will not match.

        GregorianCalendar gregorianCalendar = new GregorianCalendar();
        gregorianCalendar.setTime(commandContext.getProcessEngineConfiguration().getClock().getCurrentTime());
        gregorianCalendar.add(Calendar.MILLISECOND, lockTimeInMillis);
        job.setLockOwner(asyncExecutor.getLockOwner());
        job.setLockExpirationTime(gregorianCalendar.getTime());
    }
}
